The present invention relates to a method for the treatment of acidic petroleum oils, such as acidic crude oils. More specifically, the invention relates to a method for reducing the acidity of acidic petroleum oils.
The problems acidic petroleum oils, and in particular acidic crude oils, cause in production and/or refining operations is well known in the art. Such problems include corrosion of refining and/or production units, piping and equipment. Thus, many refiners refuse to purchase high acid crude oils or they purchase them only at significant price discounts.
The standard method used to treat acidic petroleum oils includes catalytic hydrotreating of the acidic petroleum oil to treat the acids. However, operationally, the acidic petroleum oil must be xe2x80x9ccleanedxe2x80x9d (desalted) prior to contact with the hydrotreating catalyst bed to avoid salt deactivation of the catalyst. The problems become circular because salt removal depends on water separation efficiency which is inhibited by the presence of acids or other polar species in the acidic petroleum oil. Thus, a producer or refiner cannot readily remove acids from the acidic petroleum oil by hydrotreating without first cleaning the acidic petroleum oil, but the acidic petroleum oil cleaning is impeded by the presence of acids.
Therefore, development of an efficient process for reducing the acidity of acidic petroleum oils would be a significant contribution to the art and to the economy.
It is, thus, an object of the present invention to provide an improved process for reducing the acidity of an acidic petroleum oil.
Another object of the present invention is to provide an improved process for hydrotreating/hydrogenating an acidic petroleum oil.
A further object of the present invention is to provide an improved process for hydrotreating/hydrogenating an acidic petroleum oil using a hydrogen donor process.
According to a first embodiment of the present invention, a process for hydrotreating acidic compounds of an acidic petroleum oil is provided and comprises contacting an acidic petroleum oil comprising at least one acidic compound with a hydrogen donor solvent at process conditions sufficient to promote hydrogen transfer from the hydrogen donor solvent to the at least one acidic compound of the acidic petroleum oil, thereby producing a treated petroleum oil.
According to a second embodiment of the present invention, the inventive process of the first embodiment can further comprise the steps of:
removing a fraction from the treated petroleum oil;
contacting the fraction with a hydrogenation catalyst in the presence of hydrogen and under process conditions sufficient to hydrogenate at least a portion of the hydrocarbons of the fraction; and
utilizing at least a portion of the fraction as the hydrogen donor solvent.
According to a third embodiment of the present invention, the inventive process of the first embodiment can further comprise the steps of:
contacting a portion of the treated petroleum oil with a hydrogenation catalyst in the presence of hydrogen and under process conditions sufficient to hydrogenate at least a portion of the hydrocarbons of the portion of the treated petroleum oil; and
utilizing at least a portion of the portion of the treated petroleum oil as the hydrogen donor solvent.
Other objects and advantages will become apparent from the detailed description and the appended claims.